Ricardo C. Barbosa*, Flavio Aloe†, Stella M. Tavares†§ , Ademir B. Silva‡

*Dentistry School , Universidade de São Paulo - São Paulo-SP-Brazil;

†Sleep-Wake Disorders Center, Universidade de São Paulo General Hospital, São Paulo-SP-Brazil;

‡Department of Neurology, Universidade Federal de São Paulo, São Paulo-SP-Brazil;

§ Sleep-Wake Disorders Center - Hospital Israelita Albert Einstein, São Paulo-SP-Brazil.

Introduction:
Sleep-disordered breathing ranges from partial airway collapse and increased upper-airway resistance manifested as loud snoring to recurrent airway total or partial collapse with the presence of respectively apneas and hypopneas. Obstructive sleep apnea syndrome (OSAS), clinically defined by episodes of apneas and/or hypopneas and symptoms of cognitive impairment, is life-threatening and has been associated with daytime sleepiness, motor vehicle accidents and cardiovascular morbity and mortality1. Reports that snoring is associated with stroke, myocardial infarction, and hypertension suggest that even mild degree of sleep-disordered breathing has negative effects. Therefore, even mild degree OSA demands an effective treatment. Although nasal CPAP is therapeutically effective, its compliance rate is poor even for more severe OSAS cases. Hence, removable intraoral appliances have become a treatment alternative for OSAS. The objective of this study is the assessment of the MLRD4 treatment efficiency in 15 SAOS subjects.

Methods:
15 patients (11M/4F), BMI range 20.33 to 31.22 with a PSG confirmed OSAS diagnosis were included.. Two BMI subgroups were created. Group A=normal weight3 (n=6; 4M/2F): BMI < 26.5 (mean=23.66 / SD=2.36). Group B=overweight - (n=9; 7M/2F): BMI>26.5 (mean=27.78 / SD=1.81). Pre-treatment and pos-treatment indexes obtained at approximately 4 months later for both groups included: RDI, Epworth Sleepiness Scale (ESS) daytime sleepiness scores2, min.SatO2%, number of arousals. Student's t-test was employed to compare groups.

Discussion:
Pre- and pos-treatment RDI, ESS, min Sat O2.% and arousals were statistically different for Group A and B confirming MLRD efficiency in this patient population. This demostrates the MLRD is RDI-based more efficient for BMI>26.5 subjects, probably due by the fact of the fat located in the posterior air space do not represents the real anatomy of airway structures.

Conclusion:
MLRD was more efficient for overweight subjects in this patient population.

Bibliography:

1 - Young T, Paita M, Dempsey J, Skatrud J, Webber S, Badr S. The occurance of sleep disordered breathing among middle aged adults. N Engl J Med 1993, 328:1230-1235.
2 - Johns MW. A New Method for Measuring Daytime Seleepiness: The Epworth Sleepiness Scale Sleep 1991, 14:540-5.
3 - Abernathy RP, Black DR. Healthy body weights: Na alternative perspective. Am J Clin Nutr, 63:3 Suppl, 1996 Mar, 448S-451S.
4 - Barbosa RC, Aloe F, Tavares SM, Silva AB. Evaluation of daytime sleepiness in 115 subjects treated with Mandibular Lingual Repositioning Device - MLRD. Sleep Res 1996; V.25 p.191.

Current Claim: Intraoral appliance-induced improvement in RDI is more intense in BMI>26.5 subjects .